Japanese society is now moving to “super-ageing” stage where human kind has not ever experienced. In the current circumstances, it is striking that the aged generation divides into two classes:the huge healthy and active upper aged and the not so few ill and poor lower aged. Furthermore, even any upper aged easily fall into the lower class, once they suffer dementia. Why? It is because the Japanese social safety nets since 1960’s cannot work to defend this fall now. One of the most important factors is the “transformation” of the family, which had been the last safety basis. This transformation means since 1980’s Japanese family has lost its own bonding force and been tolerant about family-diversity. As a result, weaker and weaker “the mutual help” of the family is getting. In this situation, what could we expect to strengthen the mutual help of caring? The answer in this paper is to be “the social re-involvement” of “the huge healthy and active aged.” In addition, their reinvolvement is also expected to extend over caring to any other social fields, such as education, technologies, politics, art or science. However, to realize this concept, we need our theoretical framework, that is, the perspective RE-AGEING. The word re-ageing means the process that the age recursively give meaning to them, not the state of being matured. This paper explains the conception of Neo-Gerontology to realize the sustainable “re-ageing society.”浜松医科大学紀要 一般教育 第30号（2016）